Portable electronic communication devices such as cellular telephones have become ubiquitous, and various kinds and models of devices have evolved to address specific needs. For example, “smart” phones often include touchscreen displays for displaying information to users and for accepting inputs from the users, and may include the capability to install application software to enhance the functions of the smart phone. Other more traditional phones may use an electromechanical keypad for entry of phone numbers to call and other information, and may use a display only for presenting information.
For some uses, specialized communication devices have been developed having greatly simplified user input interfaces. Some devices may lack any graphical display, and may include limited input capability, for example a single button for initiating a call to a previously-specified telephone number. While such a simplified user input interface is helpful to avoid mistakes and confusion on the part of the user of the device, the simplification comes at the cost of flexibility. For example, the device may have capabilities that are difficult or impossible to utilize using such a simplified input interface.
Some prior art devices with single-button user interfaces have prescribed elaborate protocols for pressing the single button to access multiple capabilities. For example, combinations of short and long button presses, closely-spaced presses (e.g., “double clicks”), and the like signal the device to take certain actions. Such systems are error prone, and difficult for the user to remember.